SnapCenter SQL backup fails with error: Failed to connect to server ServerName. Login failed for user UserName

Applies to

• SnapCenter (SC) 4.1 and higher
• SnapCenter Plug-In for SQL (SCSQL) 4.1 and higher

Issue

Backup failure in SCSQL

• Failed to connect SQL server
• Login failed
• Error message in SMSQL log:

DEBUG SmSql_22499 PID=[51744] TID=[9] GetSqlAccess Enter
DEBUG SmSql_22499 PID=[51744] TID=[9] Connecting to SQL Server: <ServerName>
ERROR SmSql_22499 PID=[51744] TID=[9] ConnectionFailureException: Failed to connect to server <ServerName>. Login failed for user <UserName>
ERROR SmSql_22499 PID=[51744] TID=[9] ErrorCode (-1), ErrorMessage (The SQL instance <InstanceName> is either stopped or the user <UserName> does not have required permission. Error: Failed to connect to server <ServerName>)
DEBUG SmSql_22499 PID=[51744] TID=[9] Retrying Sql connection with user: <UserName>
DEBUG SmSql_22499 PID=[51744] TID=[9] Connecting to SQL Server: <ServerName>
ERROR SmSql_22499 PID=[51744] TID=[9] ConnectionFailureException: The user name or password is incorrect.
ERROR SmSql_22499 PID=[51744] TID=[9] ErrorCode (-1), ErrorMessage (The SQL instance <InstanceName> is either stopped or the user <UserName> does not have required permission. Error: The user name or password is incorrect.

Error message in SQL error log:
Logon       Error: 18456, Severity: 14, State: 11.
Logon       Login failed for user <UserName>. Reason: Token-based server access validation failed with an infrastructure error.